I kinda understand where WhatMeWorry is coming from. A mathematician would obviously find the bottom-up orientation of bitmaps to be intuitive, but when a programmer thinks about the framebuffer, the natural orientation is top-down. This is orientation in which the screen is refreshed, and all the primitives are rasterized. So as a programmer, bottom-down would perhaps be more consistent. The fact that many UNIX systems flip the images and the graphical axis upside down is to make it more intuitive for mathematicians.